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Abstract:
This study uses fMRI to determine the brain response to the
threatening meaning of auditory verbal stories. Six normal
volunteers listened to threatening stories alternating with neutral
stories (8 cycles, 16 seconds per story). Sixteen coronal images
were acquired every 2 seconds (64x64, single shot echo planar
flash, TE=40), capturing approximately the entire cortex. The
correlation coefficient between the time-course of the response and
a reference vector reflecting the time-course of the task
presentation was computed at each pixel. Significant activity at
each pixel was determined using a ranking procedure. A cortical
region was judged to be significantly activated if it contained at
least 2 activated pixels. All of the subjects showed significant
activity in the left inferior parietal lobe in the region of the
supramarginal gyrus (Brodmann's Area 40). A subset of the subjects
also showed activity in the left anterior middle frontal gyrus. The
supramarginal gyrus is believed to be involved in language
processing, and the middle frontal gyrus may be involved in
regulating attention. These data suggest that the threatening
meaning of the stories is associated with increased activity in
brain regions also involved in responding to non-threatening
language stimuli.
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